1. Field of the Invention
The present invention relates to a device to atomizing the fuel for an internal-combustion engine.
2. Description of the Prior Art
An internal-combustion engine having a fuel-supply system which has an electromagnetic fuel injection valve and intermittently injects liquid fuel into an air-intake manifold at low pressure generally has difficulty in promoting the atomization of fuel so as to improve combustion and the quality of exhaust.
In order to promote the atomization of fuel, air is injected into the air-intake manifold so as to collide the air with the injected fuel.
A conventional air-supply method utilizes the difference in the pressure of the open air and the pressure in the air-intake manifold. In this method, there is a defect in that a sufficient supply of air cannot be obtained if there is a decreasing pressure difference between the pressure of the open air and the pressure in the air-intake manifold when the throttle valve is opened wider. In order to improve this defect, there is another method in which an air pump is used. The method in which an air pump is used can improve the above-mentioned defect. However, the method has two disadvantages. One disadvantage is that a large air pump is required, and the other disadvantage is that a comparatively high power is required to drive the air pump.
According to an investigation made by the inventors of the present invention, in the case of the electromagnetic fuel-injection system, used in passenger cars presently on the market which have a four-cylinder engine and a cylinder volume of 1,600 cubic centimeters, air having at least a flow rate of 100 liters per minute and a pressure of 1 kg/cm.sup.2 is necessary to sufficiently atomize the fuel. In this case, the output power of the air pump must be at least 163 watts and therefore a comparatively high power is required to drive the pump.
The electronic control-type fuel-injection system used in the present invention is described, for example, in the new automobile instructions manual of TOYOTA CRESTA, pages 80 through 101, published in April 1980.
The present invention is proposed in order to overcome the above-mentioned disadvantages.